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Biomedical subjects

K Hirai

Publications and source records attributed to K Hirai.

At least 19 recordsLinked to original sources
PubMed2006

Analysis of GM-CSF gene polymorphisms (3606T/C and 3928C/T) in Japanese patients with atopic dermatitis.

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is thought to play an important role in the pathogenesis of atopic dermatitis. To examine whether GM-CSF single nucleotide polymorphisms (SNPs) are associated with susceptibility to atopic dermatitis, we investigated the genotype and allele frequencies of the SNPs 3606T/C and 3928C/T of the GM-CSF gene in 181 Japanese patients with atopic dermatitis and 100 controls, using a PCR restriction fragment length polymorphism method. A strong linkage disequilibrium existed between the polymorphisms 3606 and 3928, suggesting two common GM-CSF haplotypes, 3606*T-3928*C and 3606*C-3928*T. However, there was no significant difference in genotype or allele frequencies between patients with atopic dermatitis and controls for either of the two polymorphisms, thus GM-CSF SNPs do not appear to be associated with susceptibility to atopic dermatitis in Japanese patients. A large-scale study is necessary to confirm these findings.

Adolescent↗
PubMed2006

Feasibility of using collagen as the base of the antifungal drug, miconazole.

The feasibility of using collagen as the base of miconazole was investigated. The addition of 33% collagen to a miconazole solution did not affect the minimal inhibitory concentration (MIC80) of the miconazole solution for Candida albicans. When 1 microg mL(-1) of miconazole in 33% collagen solution was plated on resin discs and dried to yield a thin membrane, the growth of C. albicans on the resin discs was nearly completely inhibited. In addition, we compared the antifungal effect of this collagen solution that contained 1 microg mL(-1) miconazole, with the antifungal effect of miconazole gel that had been diluted with glycerol (the main component of miconazole gel) to yield a final concentration of 1 microg mL(-1) of miconazole; as a result, we found that the collagen solution containing 1 microg mL(-1) miconazole had a stronger antifungal effect. In conclusion, our results demonstrated that it may be feasible to use collagen as the base of miconazole instead of glycerol, and suggest that a collagen-based miconazole solution would have a stronger antifungal effect than commercially available miconazole gel. Collagen-based miconazole solution may be useful for the treatment of Candida-associated denture stomatitis.

Antifungal Agents↗
PubMed2006

Nutritional status of people living in Dzong village, in the northern mountainous area of Nepal.

A nutritional survey was carried out among residents (39 males and 46 females) of Dzong village in the northern area of the Gandaki region of Nepal. The results were compared with our previous findings. The mean body mass index value was under 21 for both sexes, but the mean percentage of body fat of females (17-19 years old, 25.8 +/- 9.4%; 20-29 years old, 31.0 +/- 8.4%) was higher than that of males (17-19 years old, 12.0 +/- 1.0%; 50-59 years old, 24.4 +/- 7.6%). Most serum nutritional markers for both sexes were generally at normal levels although the iron levels were lower and packed red cell volume levels were higher than normal. As determined by results of the 24-hr dietary recall survey, the main food groups consumed by both sexes were cereals, potatoes, pulses, meats and vegetables. The mean daily intake of nutrients was similar for both sexes, with a few exceptions. The relatively high serum TG levels of the subjects may have been due to the high consumption of carbohydrate-laden cereals. The amounts of food consumed were not adequate, resulting in a latent and chronic deficiency of nutrients, especially calcium and iron. These results suggest that improvements in the nutritional status of this group of people are necessary.

Adolescent↗
PubMed2005

Dipeptidyl peptidase IV of Streptococcus anginosus: purification and characterization.

We found that N-unblocked nine p-nitroanilde derivatives of amino acids or peptides were hydrolyzed by the crude cell extracts of Streptococcus anginosus NCTC 10713. Then dipeptidyl peptidase IV was purified 323-fold by the procedures including ammonium sulfate concentration, anion exchange chromatography (twice), gel filtration (twice), hydrophobic interaction chromatography, and isoelectric focusing. The molecular weight was calculated as 84 kDa, and the isoelectric point was 4.9. The enzyme hydrolyzed mainly dipeptides containing proline residues at P1 position. It was strongly inhibited by serine enzyme inhibitors. General protease inhibitors, metal chelators, thiol alkylating agent, reducing agent, and several metal ions had no effect on the enzyme activity. Optimum pH for the activity was found at 7.0. The enzyme was mostly inactivated by heating at 50 degrees C for 15 min.

Chromatography, Gel↗
PubMed2005

Effect of inhaled corticosteroid on an immunoreactive thymus and activation-regulated chemokine expression in the bronchial biopsies from asthmatics.

BACKGROUND: Bronchial asthma is characterized by airway inflammation, notably because of eosinophils and T cells. Thymus and activation-regulated chemokine (TARC) is known to selectively attract Th2 cells, and is increased in response to interleukin (IL)-4 and IL-13, which share a common receptor, IL-4 receptor alpha (IL-4Ralpha). While corticosteroids have proven, very effective in modifying airway inflammation, the effect of corticosteroids on TARC in asthmatics has been little studied. OBJECTIVE: We examined the effects of inhaled budesonide (BUD) on the expression of TARC and the number of inflammatory cells in bronchial biopsy specimens taken from asthma patients. METHODS: Inhaled BUD 800 mug daily, or placebo was administered for 3 months in a double-blind, parallel-group study, and bronchial biopsies were performed before and after treatment. Biopsy specimens were examined by immunocytochemistry. RESULTS: We observed a significant decrease in the epithelial expression of TARC (P < 0.01) in the BUD group compared with the placebo group. This was accompanied by decreases in the number of eosinophils (P < 0.01), CD3(+) T cells (P < 0.05), and CD4(+) T cells (P < 0.01). A significant correlation was found between changes in epithelial TARC and in IL-4Ralpha immunoreactivity (r(s) = 0.66, P < 0.01). CONCLUSIONS: These findings suggest that corticosteroid asthma treatment can reduce infiltration of the airway by inflammatory cells, an effect modulated by down-regulation of bronchial epithelial TARC expression.

Administration, Inhalation↗
PubMed2005

[Concomitant off-pump coronary artery bypass and left lower lobectomy for lung cancer with pneumoconiosis].

Surgical strategy for patients for lung cancer with coronary disease remains controversial. We performed concomitant off-pump coronary artery bypass grafting (off-pump CABG: OPCAB) and left lower lobectomy with ND 2a lymph nodes dissection for lung cancer with pneumoconiosis. After CABG, due to fixed adhesion of peribronchial lymph node, left lower lobectomy was hard to carry out. Postoperative management was done with much difficulty for massive sputum and pneumonia caused by chronic inflammatory lung disease. As a result, postoperative course has been uneventful for 2 years after operation. In the concomitant OPCAB and lung resection with chronic inflammatory lung disease, whether the synchronous or 2 periods operation was appropriate was still unknown. We think that careful pre- and intraoperative assessment for this disease is important.

Aged↗
PubMed2004

Gene expression relevant to osteoclastogenesis in the synovium and bone marrow of mature rats with collagen-induced arthritis.

OBJECTIVES: To investigate gene expression relevant to osteoclastogenesis in the synovium and bone marrow during the development of collagen-induced arthritis (CIA) in mature rats. METHODS: Total messenger RNAs (mRNAs) were obtained from CIA synovium and bone marrow after immunization. First, reverse transcriptase-polymerase chain reactions (RT-PCR) were carried out to detect the mRNA encoding receptor activator of NF-kappaB (RANK), RANK ligand (RANKL), osteoprotegerin (OPG), tumour necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6 and the osteoclast markers tartrate-resistant acid phosphatase (TRAP) and cathepsin K. Secondly, the genes detected clearly by RT-PCR were quantified using real-time PCR. RESULTS: In the synovium, expression of all genes was confirmed by specific single bands in RT-PCR. In real-time PCR, the expression levels of TNF-alpha, IL-1beta, IL-6, RANKL, TRAP and cathepsin K mRNA increased, whereas the expression levels of RANK and OPG were unchanged and decreased respectively. RANKL expression was highly correlated with the two osteoclast markers. In the bone marrow, RT-PCR did not clearly detect the expression of IL-6, RANKL or OPG mRNA. Quantitative real-time PCR showed that TNF-alpha, RANK and TRAP mRNA expression did not change significantly with time, and that IL-1beta and cathepsin K changed slightly compared with those in the synovium. CONCLUSIONS: In the early stages of arthritis, synovial RANKL is closely involved in osteoclastogenesis, and various changes in synovial cytokines, including down-regulation of OPG, probably accelerate osteoclast formation. In contrast, cytokine mRNA in the bone marrow showed little fluctuation. We suggest that synovial cytokines affect osteoclastogenesis not only in the synovium but in the bone marrow.

Animals↗
PubMed2004

Proliferation of cultured human gingival fibroblasts caused by isradipine, a dihydropyridine-derivative calcium antagonist.

As it was reported earlier that isradipine, a Ca superset 2+ antagonist of dihydropyridine derivative class, caused regression of nifedipine-induced hyperplasia of human gingiva, experiments were performed to examine whether or not isradipine would solely inhibit the proliferation of cultured gingival fibroblasts. Normal human gingival fibroblast Gin-1 cells were used to test the impact of this medication. Fibroblast proliferation in the presence of isradipine (10 microM) was examined by using the reagent water-soluble tetrazolium-1 (WST-1). The level of basic fibroblast growth factor (bFGF) in the cell-free supernatant of each well was determined by using an enzyme-linked immunosorvent assay (ELISA) kit. The production of type I collagen was assayed by ELISA. Isradipine significantly enhanced the cell proliferation from the second day of the culture period. Also, isradipine raised the level of bFGF in the culture medium. The same concentration, also significantly enhanced the production of type I collagen. In conclusion, we were able to prove that isradipine causes the proliferation of cultured gingival fibroblasts as well as other dihydropyridine-derivative Ca superset 2+ antagonists do. In order to prevent the gingival overgrowth, it is advisable to be very careful in the use of isradipine as a therapy for hypertension and other indications.

Calcium↗
PubMed2004

A new cytochemical method for ultrastructural localization of Co2+ in rat hippocampal CA1 pyramidal neurons in vitro.

This paper describes new cytochemical method for the ultrastructural localization of Co(2+) following blockade of synaptic transmission. In the CA1 region of rat hippocampal slices, electrical stimulation of the Schaffer collaterals elicited field excitatory postsynaptic potentials (fEPSPs). The fEPSPs were completely blocked within 2 min after the addition of Co(2+) (2 mM). The slice was then fixed and precipitated Co(2+) was examined by means of a solution containing 2.5% glutaraldehyde and 10 mM K(3)[Fe(3+)(CN)(6)] in 90 mM NaCl. Electron spectroscopic imaging confirmed Co in the precipitate. The precipitates were found as clusters on the membranes of the fine apical dendrites and their spine heads of CA1 pyramidal neurons. No clustered precipitate was found when slices were treated: (1) without Co(2+); (2) after recovery from the Co(2+)-induced blockade of fEPSPs; (3) without electrical stimulation of the Schaffer collaterals; and (4) with dl-2-amino-5-phosphonopentanoate and 6-cyano-7-nitroquinoxaline-2,3-dione. After administrating glutamate (5 mM) in the presence of tetrodotoxin (1 microM) and Co(2+), precipitates were found on dendritic membranes and spine heads. These results indicate that the Schaffer collaterals stimulation induces the binding of Co(2+) on CA1 pyramidal neuron membrane.

2-Amino-5-phosphonovalerate↗
PubMed2004

Differential modulation of human basophil functions through prostaglandin D2 receptors DP and chemoattractant receptor-homologous molecule expressed on Th2 cells/DP2.

BACKGROUND: Both prostaglandin (PG) D receptor (DP) and CRTH2 (chemoattractant receptor-homologous molecule expressed on Th2 cells)/DP2 are high-affinity receptors for PGD2. Previous studies have demonstrated that PGD2 enhances releasability and induces CRTH2/DP2-mediated migration in human basophils, but the precise effects of PGD2 on basophils as well as receptor usage have not been fully clarified. OBJECTIVE: We comprehensively explored the roles of DP and CRTH2/DP2 in basophil functions by using selective agonists and antagonists for each receptor. METHODS: DP and CRTH2/DP2 transcripts were quantified by real-time PCR. We studied the effects of selective agonists (DP: BW245C; CRTH2/DP2: 13,14-dihydro-15-keto (DK)-PGD2) and/or antagonists (DP: BWA868C; CRTH2/DP2: ramatroban) on Ca2+ mobilization, migration, degranulation, CD11b expression and survival of human basophils. RESULTS: Basophils expressed transcripts of both DP and CRTH2/DP2, but the levels of CRTH2/DP2 transcripts were ca. 100-fold higher compared with DP transcripts. Ca2+ influx was induced in basophils by either PGD2 or DK-PGD2/CRTH2 agonist but not by BW245C/DP agonist. Basophils treated with PGD2 were completely desensitized to subsequent stimulation with DK-PGD2, but not vice versa. DK-PGD2 as well as PGD2 up-regulated CD11b expression, induced migration and enhanced degranulation, and those effects were completely antagonized by ramatroban/CRTH2 antagonist. In contrast, BW245C/DP agonist exhibited an inhibitory effect on basophil migration and IgE-mediated degranulation, and the migration inhibitory effect was effectively antagonized by BWA868C/DP antagonist. On the other hand, while PGD2 significantly shortened the basophil life-span, neither DK-PGD2/CRTH2 agonist nor BW245C/DP agonist did. CONCLUSION: CRTH2/DP2 is primarily responsible for the pro-inflammatory effects of PGD2 on human basophils, while DP introduces negative signals capable of antagonizing the effects of CRTH2/DP2 in these cells. The effects of PGD2 on longevity imply a mechanism(s) other than via DP or CRTH2/DP2. CRTH2/DP2 on basophils may afford opportunities for therapeutic targeting in allergic inflammation.

Basophils↗
PubMed2004

Detecting human CD34+ and CD34- hematopoietic stem and progenitor cells using a Sysmex automated hematology analyzer.

In clinical medicine, particularly in the newly developing stem cell therapies required to support the practice of regenerative medicine, the measurement of both CD34+ and CD34- hematopoietic stem cells (HSC)/hematopoietic progenitor cells (HPC) is important in obtaining more accurate information about the total HSC/HPC content in various stem/progenitor cell sources. We report the results of an investigation into methods of detecting CD34+ and CD34- HSC/HPC using the immature information (IMI) channel incorporated into the Sysmex XE-2100 and SE-9000 automated hematology analyzers. In this study, CD34+ and CD34- HSC/HPC were separated by immunologic methods and quantified by flow cytometry (FACScan) and IMI channel analysis. In addition, CD34-/CD133+ HSC were prepared by a sequential antibody-based positive selection strategy. These cells appeared in the same area as CD34+ cells in the IMI channel of the automated hematology analyzer. These findings confirmed that an automated hematology analyzer can be used to measure both CD34+ and CD34- HSC. These results may explain the difference in HSC/HPC counts sometimes observed between the automated hematology analyzer and flow cytometric methods for CD34+ measurement. The results of this study demonstrated the potential of automated cell counting methods for measuring HSC content in cellular products for both research and clinical applications.

AC133 Antigen↗
PubMed2003

Oxidative stress and predominant Abeta42(43) deposition in myopathies with rimmed vacuoles.

This study was undertaken to determine the C terminus of amyloid beta protein (Abeta), accumulated in vacuolated muscle fibers, and compare these findings to the level of oxidative stress. Eight patients with myopathies characterized by rimmed vacuoles (RVs) were analyzed. Monoclonal antibodies specific to Abeta40 or Abeta42(43) revealed that the Abeta42(43) immunoreactivity was solely distributed in the vacuolated muscle fibers, and that only a part was also immunopositive for anti-Abeta40. Quantitative analyses in four specimens, in which eight or more vacuolated muscle fibers were observed, revealed that the mean incidence of Abeta42(43)-positive muscle fibers was 79.5+/-6.2% in total vacuolated muscle fibers, whereas that of the Abeta40-positive fibers was 42.9+/-12.6%. The predominance of Abeta42(43) deposition was statistically significant ( P<0.05). Abeta deposition was then compared with the distribution of oxidative nucleic acid damage in muscle fibers using a monoclonal antibody against 8-hydroxy-2'-deoxyguanosine and 8-hydroxyguanosine (8OHdG&G). The cytoplasmic staining for anti-8OHdG&G was found not only in vacuolated muscle fibers, but also in other muscle fibers including morphologically normal ones. Positive staining was completely abolished by RNase pretreatment and, thus, was suggested to reflect an increase of cellular RNA oxidation. The distribution of 8OHdG&G was much broader than the Abeta deposition. These data suggest that Abeta42(43) is predominantly involved in the pathogenesis of muscle fiber degeneration with RVs, and that oxidative damage may precede Abeta deposition in muscle fibers and play a key role in the pathomechanism of myopathies with RVs.

Adult↗
PubMed2003

NTP and PCr responses to hypoxia by hypothermic and normothermic respiring, superfused, neonatal rat cerebrocortical slices: an NMR spectroscopy study at 14.1 Tesla.

Although mechanisms of hypothermic neuroprotection during oxygen deprivation have long been investigated, further characterizations of various molecular mechanisms are appropriate. Anticipating future studies of hypothermia and hypoxia/ischemia, we investigated the extent to which our ex vivo, NMR-based, superfused brain slice model might be helpful. (Slices are approximately 350 microm thick, with 18 slices per 8 mm NMR tube.) 31P NMR spectroscopic measurements were made of hypothermia-induced changes in high energy phosphates, while simultaneously monitoring and controlling tissue temperature, using 1H NMR, the high spectroscopic resolution available at 14.1 Tesla (600 MHz for protons), and a recently published protocol. NTP and PCr concentrations in healthy, well-oxygenated slices decreased to (55 +/- 15)% and (66 +/- 30)% of their respective values at 28.0 degrees C when warmed to 38.0 degrees C, in approximate agreement with earlier in vivo studies by others. During 30 min hypoxia NTP and PCr decreased to non-observable values, regardless of temperature. After reoxygenation, NTP and PCr recoveries as percentages of respective prehypoxia values were (63% +/- 16%; 70%) +/- 5%) for hypothermic slices (28.0 degrees C), and (46% +/- 13%; 41% +/- hypothermic neuroprotection during oxygen deprivation in this model, which appears suitable for use in further studies.

Animals↗
PubMed2003

Akt phosphorylation and cell survival after hypoxia-induced cytochrome c release in superfused respiring neonatal rat cerebrocortical slices.

Phosphorylation of Akt before hypoxia (30 min) and during reoxygenation (4 h) was evaluated in superperfused neonatal rat cerebrocortical slices (350 microm, P7, Sprague-Dawley). Cytosolic cytochrome c intensities in Western blots, which were increased at the end of hypoxia. were decreased during reoxygenation. Western blot intensities of phosphorylated Akt (phospho-Akt), nearly undetectable at the end of hypoxia, recovered quickly during reoxygenation, in a trend opposite that for cytochrome c. At 1.5 h and 4 h after hypoxia they became larger or the same as before hypoxia. Total Akt was unchanged by hypoxia and reoxygenation. Phosphocreatine (PCr) and nucleotide triphosphates (NTP) were measured in parallel 14.1 Tesla ex vivo 31P NMR superfused brain slice studies. PCr and alpha-NTP were nearly undetectable at the end of hypoxia. Although they recovered quickly after hypoxia, they were lower than before hypoxia. Reductions in phospho-Akt during hypoxia were consistent with the general unavailability of basic high energy phosphates. Preferential phosphorylation of Akt after hypoxia suggested that substantial reductions in intracellular energy, as indicated by PCr and NTP, might be tolerated by processes important for generating phospho-Akt. Additionally, the post-hypoxia increase in phospho-Akt might have contributed to concomitant reductions in cytosolic cytochrome c.

Animals↗
PubMed2003

Purification and partial characterization of a dipeptidyl peptidase from Prevotella intermedia.

A peptidase hydrolyzed X-Pro-p-nitroanilide was purified from the cell extract of Prevotella intermedia ATCC 25611 by ion-exchange chromatography and hydrophobic interaction chromatography. The purified enzyme exhibited a molecular size of 74 kDa from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the maximum enzyme activity was found between pH 7.0 and pH 7.5. This peptidase was a serine enzyme and hydrolyzed Lys-Pro-p-nitroanilide, Arg-Pro-p-nitroanilide, and Ala-Pro-p-nitroanilide, but Lys-Ala-p-nitroanilide was not split. The enzyme may be classified as a dipeptidyl peptidase IV.

Amino Acid Sequence↗
PubMed2003

Development and clinical application of nucleated red blood cell counting and staging on the automated haematology analyser XE-2100.

We initially developed a new flow cytometric (FCM) reference method for the enumeration and staging of nucleated red blood cells (NRBC) in 1997 [Wang et al., 1998 (XIth International Symposium on Technological Innovations in Laboratory Haematology, Banff, Canada, 1998); Tsuji et al., 1999 (Cytometry, 1999)]. The method used CD45 antibody and propidium iodide staining to separate NRBCs from other cells. Accuracy and precision were enhanced because larger numbers of cells were counted than was possible with the manual method. We also developed a method for automated NRBC counting on a haematology analyser, the XE-2100 (Wang, 1988). NRBC were separated from other cells using a special lysing buffer and a fluorescent dye. The XE-2100 was found to detect peripheral and cord blood NRBC accurately and precisely when compared with cell morphology or FCM control methods. The FCM NRBC staging method was established through the identification of different NRBC populations following the novel staining and lysing method. To evaluate the method further, we sorted samples containing NRBCs using a FACSort and investigated NRBC staging on the Sysmex XE-2100 based on the cell sorting results. Data were analysed using special software (ida). First, we used the data in various parameter combinations. We then established gates to classify the NRBC populations. Finally, we analysed blood specimens from patients with different types of diseases to explore possible clinical applications.

Blood Cells↗
PubMed2003

Long-term effects of hormone replacement therapy on bone mineral density in girls oophorectomized in adolescence.

The object of this study was to examine the effects of hormone replacement therapy (HRT) on bone mineral density (BMD) and physical development in oophorectomized adolescent girls. Two adolescent girls had bilateral ovaries removed as the treatment of advanced ovarian neoplasms at 12 years of age, and have been receiving HRT for more than 10 years. The changes in BMD and physical development were recorded. Both patients entered puberty and developed mature female physiques, despite the 3 years' absence of estrogen exposure immediately after oophorectomy. BMD recovered soon after the start of HRT and was kept within the normal range. Normal physical development, including bone mineral density, can be achieved with HRT in adolescent girls castrated before puberty.

Body Height↗